libs/vamp-plugins/SpectralCentroid.cpp

   1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
   2
   3 /*
   4     Vamp
   5
   6     An API for audio analysis and feature extraction plugins.
   7
   8     Centre for Digital Music, Queen Mary, University of London.
   9     Copyright 2006 Chris Cannam.
  10
  11     Permission is hereby granted, free of charge, to any person
  12     obtaining a copy of this software and associated documentation
  13     files (the "Software"), to deal in the Software without
  14     restriction, including without limitation the rights to use, copy,
  15     modify, merge, publish, distribute, sublicense, and/or sell copies
  16     of the Software, and to permit persons to whom the Software is
  17     furnished to do so, subject to the following conditions:
  18
  19     The above copyright notice and this permission notice shall be
  20     included in all copies or substantial portions of the Software.
  21
  22     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
  26     ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
  27     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29
  30     Except as contained in this notice, the names of the Centre for
  31     Digital Music; Queen Mary, University of London; and Chris Cannam
  32     shall not be used in advertising or otherwise to promote the sale,
  33     use or other dealings in this Software without prior written
  34     authorization.
  35 */
  36
  37 #include "SpectralCentroid.h"
  38
  39 using std::string;
  40 using std::vector;
  41 using std::cerr;
  42 using std::endl;
  43
  44 #include <cmath>
  45
  46
  47 SpectralCentroid::SpectralCentroid(float inputSampleRate) :
  48     Plugin(inputSampleRate),
  49     m_stepSize(0),
  50     m_blockSize(0)
  51 {
  52 }
  53
  54 SpectralCentroid::~SpectralCentroid()
  55 {
  56 }
  57
  58 string
  59 SpectralCentroid::getIdentifier() const
  60 {
  61     return "spectralcentroid";
  62 }
  63
  64 string
  65 SpectralCentroid::getName() const
  66 {
  67     return "Spectral Centroid";
  68 }
  69
  70 string
  71 SpectralCentroid::getDescription() const
  72 {
  73     return "Calculate the centroid frequency of the spectrum of the input signal";
  74 }
  75
  76 string
  77 SpectralCentroid::getMaker() const
  78 {
  79     return "Vamp SDK Example Plugins";
  80 }
  81
  82 int
  83 SpectralCentroid::getPluginVersion() const
  84 {
  85     return 2;
  86 }
  87
  88 string
  89 SpectralCentroid::getCopyright() const
  90 {
  91     return "Freely redistributable (BSD license)";
  92 }
  93
  94 bool
  95 SpectralCentroid::initialise(size_t channels, size_t stepSize, size_t blockSize)
  96 {
  97     if (channels < getMinChannelCount() ||
  98         channels > getMaxChannelCount()) return false;
  99
 100     m_stepSize = stepSize;
 101     m_blockSize = blockSize;
 102
 103     return true;
 104 }
 105
 106 void
 107 SpectralCentroid::reset()
 108 {
 109 }
 110
 111 SpectralCentroid::OutputList
 112 SpectralCentroid::getOutputDescriptors() const
 113 {
 114     OutputList list;
 115
 116     OutputDescriptor d;
 117     d.identifier = "logcentroid";
 118     d.name = "Log Frequency Centroid";
 119     d.description = "Centroid of the log weighted frequency spectrum";
 120     d.unit = "Hz";
 121     d.hasFixedBinCount = true;
 122     d.binCount = 1;
 123     d.hasKnownExtents = false;
 124     d.isQuantized = false;
 125     d.sampleType = OutputDescriptor::OneSamplePerStep;
 126     list.push_back(d);
 127
 128     d.identifier = "linearcentroid";
 129     d.name = "Linear Frequency Centroid";
 130     d.description = "Centroid of the linear frequency spectrum";
 131     list.push_back(d);
 132
 133     return list;
 134 }
 135
 136 SpectralCentroid::FeatureSet
 137 SpectralCentroid::process(const float *const *inputBuffers, Vamp::RealTime)
 138 {
 139     if (m_stepSize == 0) {
 140         cerr << "ERROR: SpectralCentroid::process: "
 141              << "SpectralCentroid has not been initialised"
 142              << endl;
 143         return FeatureSet();
 144     }
 145
 146     double numLin = 0.0, numLog = 0.0, denom = 0.0;
 147
 148     for (size_t i = 1; i <= m_blockSize/2; ++i) {
 149         double freq = (double(i) * m_inputSampleRate) / m_blockSize;
 150         double real = inputBuffers[0][i*2];
 151         double imag = inputBuffers[0][i*2 + 1];
 152         double power = sqrt(real * real + imag * imag) / (m_blockSize/2);
 153         numLin += freq * power;
 154         numLog += log10f(freq) * power;
 155         denom += power;
 156     }
 157
 158     FeatureSet returnFeatures;
 159
 160 //    std::cerr << "power " << denom << ", block size " << m_blockSize << std::endl;
 161
 162     if (denom != 0.0) {
 163         float centroidLin = float(numLin / denom);
 164         float centroidLog = powf(10, float(numLog / denom));
 165
 166         Feature feature;
 167         feature.hasTimestamp = false;
 168         if (!std::isnan(centroidLog) && !std::isinf(centroidLog)) {
 169             feature.values.push_back(centroidLog);
 170         }
 171         returnFeatures[0].push_back(feature);
 172
 173         feature.values.clear();
 174         if (!std::isnan(centroidLin) && !std::isinf(centroidLin)) {
 175             feature.values.push_back(centroidLin);
 176         }
 177         returnFeatures[1].push_back(feature);
 178     }
 179
 180     return returnFeatures;
 181 }
 182
 183 SpectralCentroid::FeatureSet
 184 SpectralCentroid::getRemainingFeatures()
 185 {
 186     return FeatureSet();
 187 }
 188